Telegraphone



March 1, 1949.

Filed May 30, 1945 T. M. SHRADER TELEGRAPHONE 3 Sheets-Sheet l ATTORNE y March 1, 1949. i SHRADER 2,463,001

TELEGRAPHONE Filed Ma so, 1945 :5 sheets-sheet 2 HVVENTUR.

u filfd ATTORNEY March 1, 1949. T. M. SHRADER 2,463,601

TELEGRAPHONE Filed May 50, 1945 s Sheets-Sheet s ATfORNA-Y enema M... 1, 1949 'rsmoaernona Terry M. Shrader, Indianapolis, Ind., minor to Radio Corporation of America. a comrlflon of Delaware Application May so, 1945. Serial No. 590,690

3 Claims. (Cl. 242-54) This invention relates to. magnetic sound recording and reproducing apparatus and has special reference to the provision of improvements in magnetic phonographs or telegraphones" of the type wherein the wire or other flexible record is enclosed in a removable casing or cartridge.

In telegraphcnes designed to accept record cartridges it is the usual practice to mount the magnetic transducer or pick-up unit within the cartridge along with the storage and take-up reels. This necessitates the use oi. a plug and socket arrangement for making the necessary electrical connections between the pick-up unit and the amplifier, microphone, loudspeaker, oscillator and other components of the set. Such a connector may become noisy with use and this possibility is augmented when the telegraphone comprises a plural-wire machine, or when the pickup unit includesdiscrete recording, reproducing and wiping coils.

In an efiort to obviate the necessity for using plug-in connectors it has previously been proposed (see British Patent 236,237, of 1925 and 236,574 of 1926) to mount the transducer or "magnetic box on top of the phonograph cabinet between two keyed spindles and to enclose the reels or spools in a detachable casing which is provided, intermediate its ends, with a slot for accommodating the magnet box. In these British patents the reels are loosely arranged at opposite ends of the casing and are provided with keyways which are designed to engage the spindle keys. The spaced apart arrangement of the reels necessitates the use of an oversize, relatively cumbersome casing. Furthermore, the difficulties incident to bringing the wire within the casing or cartridge into register with the magnet box and the spindle keys into register with the separate reel keyways, renders the assembly of the said parts far more difiicult than is desirable in the case of an instrument whose use may be entrusted to an unskilled operator.

Accordingly, .the principal object of the present invention to provide a magnetic recording and reproducing apparatus which shall obviate the use of plug-type connectors and .pther potential sources of noise and which shall dispense with the clutching, keying, wire-positioning and other alignment problems incident to the use of present-day telegraphones.

Another and related Object of the invention is to provide an improved telegraphone wherein the record-cartridge within aslot or socket in the cabinet oi the set.

Another object of the present invention is to provide a record-cartridge wherein the record may be rewound on its storage reel simply by reversing the position of the cartridge within its socket.

Another object or the present invention is to provide a record cartridge incorporating a direct-reading dial or indicator, the indicator being of a construction calculated to decrease rather than to increasethe weight of the cartridge.

Another and related object of the present invention is to provide an inexpensive, light-weight, yet rugged record cartridge, and one which may be sent through the U. 8. mail in an ordinary envelope.

Another object of the present invention is to provide a simplified stop for disconnecting the reel and reel driving mechanisms when the record has completed its journey from one reel to another. a

Still another object of the'present invention is to provide an extremely simple,.yet reliable tensioning arrangement for a wire or other reelabl'e record. I

Other objects and advantages will be apparent and the invention itself will be best understood upon reference to the following speciflcation and to the accompanying drawings, wherein:

Fig. 1 is a front elevation, Fig. 2 a side elevation, Fig. 3 is an elevation with the cover removed and Fig. 4 is an exploded view of-a telegraphone record cartridge constructed in accordance with the principle of the invention.

Fig. 6 is an enlarged side elevation oi the wire guide, looking in the direction oilthe arrows VI- VI in Fig. 5, v

Figs. Z and 8 are end views of the wire guide, looking in the direction of the arrows VII-VII and VIIIVIII respectively, of Fig. 5,

Fig. 9 is a front elevation of a telegraphone or magnetic phonograph having the record cartridge of Figs. 1 to 8 inserted therein in a'position to be played, and I Fig. 10 is a sectional view taken on the lin Iii-X of Fig. 9.

In the drawings, wherein like reference characters represent the same parts in all figures, -i (Fig. 10) designates generally ametal chassis Y respectively. The rear cartridge.

compartment B-acoommodates a motor l having a rubber tired stubshaft or drive roller 8 which extends into the front compartment 6 through a suitable'aperture 8 in the intermediate wall 4. This relatively narrower front compartment comprises an opentopped receptacle or socket for a removable record cartridge l0.

As will hereinafter morefully appear .the cartridge It) contains a wire or other reelable magnetic .record It and reel assembly therefor, including tw o reels l2 and I8 and a wire guide I! over which the record travels in its journey from one reel to the other. 7

It will be observed upon inspection of Figs. 1

- to '4 inclusive that the casing of the cartridge is of bi-part construction and that each of its internally dished complementary halves l5 and I6 is provided with a slot l1, H which extends upwardly along the vertical axis of the cartridge from its bottom or leading edge l8 to a point Just beyond the periphery of the reel l2 (or l8) These vertical slots l'l, ll are dimensioned to space for a bent arm 18 (see Fig. which is secured at its-lower ,end to the inner surface of the rear wall 4 of the socket and extends upwardly into the wire-receiving groove of the drivers reel i2. As viewed in Fig. 10 the inner reel I3 is the ftake-up reel, thatis to say the wire I I is taken-up by the said reel as it is drawn oil the other or storage reel 12. It will now be apparent that as the wire is piled-up in the groove of reel l3 it will eventually touch the end of the arm l9 whereupon the cartridge will be urged upwardly in its socket a suflicient distance to lift the periphery of the said reel out of engagement with the driving 'roller 8 and thus prevent the wire from running completely off the other reel l2.

transducer 28 for the magnetic wire II. This unit 28 is preferably supported upon a leaf spring 2| at the bottom of the socket whereby the pole-'- sert 28 around which the wire ii is led from one reel to the other. This insert i4 comprises two slotted end portions Ila, Mb for guiding the wire between the reels and an exposed unslotted central part llcagainst which the pole pieces 22 of the transducer (Figs. 9 and 10) are urged by e the leaf-spring 2| at the base of the socket 5.

1 upon which the reels l2 and 18 rotate. These The socket 5 also accommodates a magnetic scribed in Henry E. Roys copending appln. Se- I rial No. 591,071 filed April 30, 1945. Such a transducer may-be used selectively, for recording, reproducing and wiping purposes, in which event it will be understood that its leads 23 (Fig.

10) should be connected to a suitable switch (not shown) having contacts individual to the wiping oscillator and the amplifier for the microphone and loudspeaker of the set.- I

Referring now particularly to Figs. 4 to 8 inclusive which show the internal structure of the The shell-like halves l5 and [8 of this'molded plastic casing are of duplicate construction and are each provided with a pair of molded-in arcuate ridges 2|,- 24': one on each side of the slot" within which the motor-(driven casing define a seat 25 for the wire-guide il in-' bearings are bored to accommodate a small bolt 28 which is provided with a nut 88 for holding the assembly together.

It will be observed that'the outer side-face of eachreel (and I8) is provided with a number of circumferentially spaced openings which communicate with the reel grooves. These openings 8| not only decrease the weight of the as sembly but also permit inspection, through a window or windows 32 in the casing, of the quantity of wire within the said grooves.- Since the reels are driven at a speed sufficient to ensure persistance of vision the quantity of wire on the storage reel can be observed throughout the recording interval. The quantity of wire available may be translated into units of time by suitable indicia on the face of the casing adjacent to the window 32.

Referring still to the self-contained direct reading indicator, it should be noted that since the inner side-surface of each reel is unperforated bility ofobtaining a false reading such as might be obtained if one could look right through the outer reel into the wire receiving groove of the inner reel. Another feature of this indicator resides in the fact the reel faces (or at least so much of them as is presented to the window) are provided with a gun-metal or other dull finish to contrast with the usually bright finish of the wire record.

Since the quality of any magnetic recording may be seriously impaired by irregularities in the speed of the wire it is essential that some means he provided for maintaining substantially uniform tension on the wire throughout the recording and playing intervals. This may be achieved, by way of example, by the provision of a pair of springs (not shown) wound in opposite directions about the common axis of the reels in the manner disclosed by Terry M. Shrader in copending appln. Serial No. 584,197 filed March 22, 1945. While this earlier described record tensioning mechanism is very compact it adds to the weight of the reel and its cost can not be absorbed in the marketing of a record cartridge designed to sell at the lowest possible price.

Accordingly, as previously indicated, the present invention contemplates the provision of a less expensive record tensioning system. This system depends for its operation upon an added "friction load" on the reels, such as may be produced by biasing the outer side surfaces of each reel into contact with the adjacent inner surfaces of the casing. To this end, referring now particularly to Figs. 10 and 4, the. outer side surface of each reel is preferably provided with a narrow rim 38 which is urged lightly yet constantly into frictional engagement with the adjacent inner surface of the casing as by means of a dished spring or washer 34 mounted between the reels. In the embodiment of the invention which has been selected for purposes of illustration the dimensions of the cartridge were substantially as follows: length 2%", maximum width 2", thickness The reels contained approximately 600 ft. of 0.004" wire. Thus, when the wire speed was 2 ft. per second the wire accommodated a 5 minute recording. The total weight of the cartridge was approximately 3 oz.

It will now be apparent that the present invention provides a reliable, yet compact and inexpensive cartridge-type telegraphone, and one which lends itself readily for use by the general public for correspondence and other purposes.

What is claimed is:

1. A cartridge for a magnetic wire record, said cartridge comprising a casing containing bearing means and a reel assembly for said wire, said reel assembly comprising a plurality of reels mounted for rotation upon said bearing means and a wire-guide upon which said wire is adapted to travel in its journey from one reel to another, said casing having an aperture adjacent to said wire guide through which energizing elements may be applied, respectively, to said wire and to said reel assembly.

2. A cartridge for a reelable magnetic record, said cartridge comprising a casing containing bearing-means and a reel assembly for said record, said reel assembly comprising a driving reel and a driven reel mounted for rotation in coaxial torque-transfer relation upon said bearing means, said casing having an aperture through which a driving element may be applied to the periphery of said driving reel.

3. In apparatus of the character described, asocket adapted to accommodate a cartridge containing an assembly including a grooved storage reel, a grooved take-up reel and a wire record wound to run between said storage and take-up reels, said cartridge having an aperture through which access may be had to said reel-grooves, driving means mounted in said socket and adapted to be received in said aperture for engaging and driving said reel assembly, and means mounted REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Fankhauser et al. N... Aug. 21, 1917 Myers Aug. 1, 1922 Thornton Nov. 13, 1928 Curran Nov. 7, 1933 Hineline Oct. 16, 1934 Laudenbach et a1. Apr. 16, 1935 Somers Dec. 5, 1944 FOREIGN PATENTS Country Date Germany July 21, 1936 Number Number 

